The present invention relates to an air filter device comprising means in the form of a mouthpiece allowing the user to grip and retain the device itself.
Owing to the continuous increase in atmospheric pollution and the particular environmental conditions of some specific manufacturing activities, the persons at risk are forced to breath through special filtering devices such as, for example, those contained in special masks.
U.S. Pat. No. 4,719,911 discloses an air filter mask provided with a mouthpiece attached to a shaft cooperating with a pair of annular retainers frictionally engaging the shaft. The mouthpiece is configured to be held between the upper lip and the upper teeth and gum of the user; this means that from one side the retaining action cannot be strong enough to assure the adhesion of the mask to the face of the user (in fact anti-suffocation means are provided), thus requiring special, very light materials that do not avoid leakage of the mask. The known mouthpiece also does not allow a quick release in the case of possible suffocation due for instance to an occlusion of the filter.
A moisture exchange material is associated with the mask of WO 94/00196.
It is also known that such masks are difficult to use because of their size and the awkward nature of the fastening devices for fixing them to the face, resulting in their being practically unusable for example in the case of cyclists and/or motorcyclists who also have to wear a protective helmet.
It is an object of the invention to provide an air filter device which is of low weight and small size and is practical and simple to fit during use and remove after use.
Another object is to provide the filter device with means for keeping it fixed to the face, which can be easily replaced in the event of breakage or the like.
These technical problems are solved according to the present invention by an air filter device which comprises means in the form of a mouthpiece enabling the device to be gripped and retained by a user.